Originally Posted by Frode Falch
How would it work if i went on a diet without any carbs for almost 5 weeks. while training hard.
If you do a ketogenic diet I think you will be fine. I have been doing it for a year now and feel healthier than ever, I always have energy.
However, at least for me, when I changed to low-carb I got weaker for a few months. Then I felt my body adapted, and now I feel I have better endurance than before.
If you want to do it properly I think you should avoid carbs before or after exercise as well since you want your body to adapt as fast as possible. The problem is that you need to make your cell utilize fat as fuel, either the one you eat, or use stored fat in the body. If you eat carbs, the body will use the glycogen as fuel as long as it's available. This will slow down the adaptation process.
Check this interview with Peter Attia if you have time, he has some experience with low-carb performance: